A Bar Chart or Bar Graph can be only used to compare values. It presents grouped data using rectangular bars whose lengths are proportional to the values that they represent. The bars can be plotted vertically or horizontally. A vertical Bar Chart is sometimes called a Column Chart. Bar charts are usually scaled so that all the data can fit on the chart. Bars on the chart can be arranged in any order. The point values can be compared between themselves (single-series chart) or values inside the category (multi-series chart). In case of several series, points are grouped by categories.